1. Field of the Invention
The present invention relates generally to a rear suspension for an automotive vehicle and more specifically to a wishbone type suspension which is so configured as to minimize the amount of toe-out which is produced under given modes of operation such as engine braking and/or permit a toe-in effect to be produced.
2. Description of the Prior Art
Japanese Utility Model First Provisional Publication No. 55-1556 published on Jan. 8, 1980 discloses a rear suspension comprising an essentially A-shaped single lower arm which is pivotally connected at its inboard end to the vehicle chassis and which has a pivot at its outboard end. A road wheel is "steerably" mounted on this pivot. The orientation of the wheel is controlled by a control rod and knuckle arm arrangement. A shock absorber strut interconnects the outboard end of the lower arm with the vehicle chassis.
However, this arrangement has suffered from the drawback that when the road wheel is subject to a force acting laterally inward toward the vehicle a relatively large toe-in is induced while in the case of a force which act toward the rear of the vehicle a notably smaller toe-in is induced.
This phenomenon is deemed to be caused by the fact that the intersection of the axis of the axle and the "king pin axis" which passes through the pivot which interconnects the suspension arm with the shock absorber strut and extends along essentially coincidentally with the axis of the strut, is notably offset from the wheel center. Thus when a force which acts in the aft direction of the vehicle is applied to the road wheel, a moment of force is generated which tends to produce toe-out and which exerts a de-stablizing effect on the suspension characteristics.